Qualitative analysis of Canadian blood and plasma donors' views on expanding donor screening eligibility for gay, bisexual, and other men who have sex with men.

BACKGROUND: In many countries, sexually active gay, bisexual and other men who have sex with men (gbMSM) continue to be screened based on their sex or gender and the sex or gender of their sexual partner. However, there is growing support that screening based on specific sexual behaviors that pose risk of transfusion transmissible infection is a better approach to donor screening. STUDY DESIGN AND METHODS: This paper reports results from Phase 1 (qualitative) of a mixed-methods study on Canadian blood and plasma donors' views on expanding eligibility for gbMSM by changing to sexual behavior-based screening. Semistructured interview data with 40 donors (whole blood = 20, plasma = 20; male = 21, female = 18, nonbinary = 1; mean age = 46.2; 10% participation rate) in Canada were analyzed using a thematic approach. RESULTS: All participants, except one, supported the change as they anticipated that at least one of three outcomes would be achieved: increasing blood supply, enhancing equity, and improving or maintaining the safety of blood supply. One donor who was more skeptical of the change questioned the scientific evidence for the change and indicated mistrust of state institutions. The discussion considers implications for blood operators' communication strategies that can be used to reduce donor discomfort with the changes to donor screening. CONCLUSION: In a nonrandom, purposive sample of 40 Canadian blood and plasma donors, most participants held favorable views regarding expanding the eligibility of gbMSM donors based on sexual risk behavior. Understanding donors' views on increasing eligibility may inform Canadian Blood Services and other blood operators as they develop their communications plans.

Anti-HNA testing of allo-exposed COVID-19 convalescent plasma donors including genetic human neutrophil antigen screening to prevent anti-HNA antibody-mediated transfusion-related acute lung injury.

BACKGROUND: Transfusion-related acute lung injury caused by antibodies against human neutrophil antigens (HNA) is a serious but rare complication associated with blood transfusion. The presence of such antibodies is most probable in donors with a transfusion/pregnancy history. During the COVID-19 pandemic period convalescent plasma (CP) containing neutralizing antibodies against SARS-CoV-2 was widely used for COVID-19 patients as a therapy in the absence of any treatment. The aim of the study was to work out a simple diagnostic algorithm of anti-HNA testing of allo-exposed CP donors including genetic HNA screening. MATERIALS AND METHODS: A total of 457 anti-HLA-negative allo-exposed CP donors were genotyped for HNA-1a/1b, HNA-3a/3b, and HNA-2, and only donors with homozygous HNA-1a/1a; HNA-3b/3b; or HNA-2null genotypes were tested for anti-HNA antibody using LabScreenMulti (One Lambda) and homozygous HNA-1b/1b using the granulocyte immunofluorescence test (GIFT) but verified using LabScreenMulti. RESULTS: Testing of 83 homozygous HNA-3b/3b; HNA-2null; or HNA-1a/1a donors revealed anti-HNA-3a antibody in one case. Testing of 181 HNA-1b/1b donors using GIFT gave 10 ambiguous results verified using LabScreenMulti which confirmed anti-HNA-1a antibody in one case. The frequency of FCGR3B*01 and *04 encoding HNA-1a was 0.34; FCGR3B*02, *03, and *05 encoding HNA-1b-0.66; SLC44A2*01 encoding HNA-3a-0.80; and SLC44A2*02 encoding HNA-3b-0.20. In 3.7% cases the HNA-2null genotype was revealed. DISCUSSION: Due to applying HNA genotyping as a primary test before anti-HNA antibody testing the serological work was limited only to HNA-homozygous donors revealing two anti-HNA immunized donors. The distribution of HNA genotypes in the cohort was similar to other Caucasian populations.

Advancing gender inclusivity for Two-Spirit, trans, nonbinary and other gender-diverse blood and plasma donors.

BACKGROUND AND OBJECTIVES: Two-Spirit, trans, nonbinary and other gender-diverse (2STGD) donors face challenges in donation. While many blood operators aim to address these challenges, to date, no empirical study with these donors has been conducted to guide their efforts. This paper reports 2STGD donors' views on a two-step approach asking donors their gender and sex assigned at birth (SAAB), and expanding gender options in donor registration. MATERIALS AND METHODS: A qualitative community-based study was conducted with 2STGD donors (n = 85) in Canada. Semi-structured, in-depth interviews were conducted from July to October 2022, audio-recorded and transcribed. Data were analysed using a thematic analytic framework. RESULTS: Participants were divided on their views of a two-step approach asking gender and SAAB. Themes underlying views in favour of this approach included the following: demonstrating validation and visibility, and treating 2STGD donors and cisgender donors alike. Themes underlying views not in favour or uncertain included potential for harm, compromising physical safety, and invalidation. All participants were in favour of expanding gender options if blood operators must know donors' gender. CONCLUSION: Results indicate that a two-step approach for all donors is not recommended unless the blood operator must know both a donor's gender and SAAB to ensure donor and/or recipient safety. Gender options should be expanded beyond binary options. Ongoing research and evidence synthesis are needed to determine how best to apply donor safety measures to nonbinary donors.

Behavioral verification and risk factors of HIV cross-population transmission in China: analysis of national surveillance data 1989-2022.

INTRODUCTION: The dynamic HIV/AIDS epidemic significantly impacts China, particularly affecting injection drug users (IDUs), former plasma donors (FPDs), men who have sex with men (MSM), and those engaging in high-risk heterosexual behavior (HRHB). This study specifically focuses on identifying the risk factors and influences that drive the spread of HIV among these population groups by performing a comprehensive analysis of contact histories of individuals diagnosed with HIV. METHODS: Data for this research were gathered from China's HIV/AIDS Comprehensive Response Information Management System (CRIMS). Contact histories were described using bar and venn diagram. Trend in engaging in HBRB among MSM were identify potential change using the Cochran-Armitage test. Logistic regression was employed to analyze the factors influencing HBRB in MSM. RESULTS: From 1989 through to 2022, a total of 1,457,218 individuals aged 15 years or older in China, who reported being infected with HIV, indicated they had one or more types of contact histories including injecting drug use, male homosexual behavior, commercial plasma donation, and high-risk heterosexual behavior. Among these, 97.0% reported a single type of contact history, while 3.0% reported having multiple contact histories. Of those with multiple contact histories, 98.0% (42,258 individuals) had engaged in HRHB. Among all HIV-infected IDUs, MSM, and FPDs, their respective proportions of engagement in HRHB were 11.8%, 5.7% and 6.2%. Prior to 2012, most were reported to be IDUs; however, subsequent to this, most reported being MSM. Factors that heightened the risk of engaging in HRHB among HIV-infected MSM included being of age between 25-34 years [adjusted odds ratio (AOR) = 1.29] or 35-44 years (AOR = 1.22), marital status such as being married (AOR = 1.23) or being divorced/widowed (AOR = 1.17), belonging to an ethnic minority (AOR = 1.29), receiving diagnosis in hospitals (AOR = 1.81), residing in rural areas (AOR = 1.12), among others. However, the risk of HRHB decreased when age ≥ 55 years (55-64 years: AOR = 0.82; ≥ 65 years: AOR = 0.64). CONCLUSION: The potential for HIV transmission among diverse populations is substantial. As such, it is imperative that strategies are implemented to mitigate the propagation of HIV to the general populace via heterosexual intercourse.

[Modern problems of plasma donation services: global experience in solving them].

As an analysis of foreign literature on donation has shown, the global market for therapy with drugs from human plasma is growing, which leads to the need for large volumes. With significant geographic imbalances in the global plasma supply and the dependence of most countries on plasma supplies from the United States, the most vulnerable are low- and middle-income countries, where the challenge of meeting the demand for plasma products requires improvements to regional plasma donation systems. An effective tool for the development of plasma collection services is compliance with the standards of plasma donation services, the development of voluntary free plasma donation, and the optimization of donor recruitment and retention processes.

Demographics of first-time donors returning for donation during the pandemic: COVID-19 convalescent plasma versus standard blood product donors.

BACKGROUND: Previous studies have demonstrated low first-time donor return rates (DRR) following catastrophic events. Little is known, however, about the influence of demographic factors on the DRR of first-time donors during the COVID-19 pandemic, including the unique motivation of COVID-19 convalescent plasma (CCP) donors as compared to non-CCP donors. STUDY DESIGN AND METHODS: Thirteen blood collection organizations submitted deidentified data from first-time CCP and non-CCP donors returning for regular (non-CCP) donations during the pandemic. DRR was calculated as frequencies. Demographic factors associated with returning donors: race/ethnicity, gender, and generation (Gen Z: 19-24, Millennial: 25-40, Gen X: 41-56, and Boomer: ≥57 years old), within the CCP and non-CCP first-time cohorts were compared using chi-square test at p < .05 statistical significance. RESULTS: From March 2020 through December 2021, there were a total of 44,274 first-time CCP and 980,201 first-time non-CCP donors. DRR were 14.6% (range 11.9%-43.3%) and 46.6% (range 10.0%-76.9%) for CCP and non-CCP cohorts, respectively. Age over 40 years (Gen X and Boomers), female gender, and White race were each associated with higher return in both donor cohorts (p < .001). For the non-CCP return donor cohort, the Millennial and Boomers were comparable. CONCLUSION: The findings demonstrate differences in returning donor trends between the two donor cohorts. The motivation of a first-time CCP donor may be different than that of a non-CCP donor. Further study to improve first-time donor engagement would be worthwhile to expand the donor base with a focus on blood donor diversity emphasizing engagement of underrepresented minorities and younger donors.

Simple prediction of COVID-19 convalescent plasma units with high levels of neutralization antibodies.

BACKGROUND: Hyperimmune convalescent COVID-19 plasma (CCP) containing anti-SARS-CoV-2 neutralizing antibodies (NAbs) was proposed as a therapeutic option for patients early in the new coronavirus disease pandemic. The efficacy of this therapy depends on the quantity of neutralizing antibodies (NAbs) in the CCP units, with titers ≥ 1:160 being recommended. The standard neutralizing tests (NTs) used for determining appropriate CCP donors are technically demanding and expensive and take several days. We explored whether they could be replaced by high-throughput serology tests and a set of available clinical data. METHODS: Our study included 1302 CCP donors after PCR-confirmed COVID-19 infection. To predict donors with high NAb titers, we built four (4) multiple logistic regression models evaluating the relationships of demographic data, COVID-19 symptoms, results of various serological testing, the period between disease and donation, and COVID-19 vaccination status. RESULTS: The analysis of the four models showed that the chemiluminescent microparticle assay (CMIA) for the quantitative determination of IgG Abs to the RBD of the S1 subunit of the SARS-CoV-2 spike protein was enough to predict the CCP units with a high NAb titer. CCP donors with respective results > 850 BAU/ml SARS-CoV-2 IgG had a high probability of attaining sufficient NAb titers. Including additional variables such as donor demographics, clinical symptoms, or time of donation into a particular predictive model did not significantly increase its sensitivity and specificity. CONCLUSION: A simple quantitative serological determination of anti-SARS-CoV-2 antibodies alone is satisfactory for recruiting CCP donors with high titer NAbs.

Long-term antibody titers variation in unvaccinated patients receiving convalescent plasma or placebo for severe SARS-CoV-2 pulmonary infection.

BACKGROUND: Convalescent plasma (CP) became a prominent treatment in the early stages of the SARS-CoV-2 pandemic. In Argentina, a randomized clinical trial was executed to compare the use of CP in inpatients with severe COVID-19 pneumonia versus placebo. No differences in clinical outcomes or overall mortality between groups were observed. We conducted a cohort study in outpatients enrolled in the trial to describe long-term antibody titer variations between CP and placebo recipients. METHODS: Patients' total SARS-CoV-2 IgG antibodies against spike protein were collected 3, 6 and 12 months after hospital discharge from August 2020 to December 2021. In addition, reinfections, deaths and vaccination status were retrieved. Statistical analysis was performed using antibody geometric mean titers (GMT). All estimations were made considering the date of the trial infusion (placebo or CP) as time 0. RESULTS: From the 93 patients included in the follow-up, 64 had received CP and 29 placebo. We excluded all 12-month measurements because they were collected after the patients' vaccination date. At 90 days post-infusion, patients had an antibody GMT of 8.1 (IQR 7.4-8.1) in the CP group and 8.8 (IQR 8.1-9.1) in the placebo group. At 180 days, both groups had a GMT of 8.1 (IQR 7.4-8.1). No statistical differences in GMT were found between CP and placebo groups at 90 days (p = 0.12) and 180 days (p = 0.25). No patients registered a new COVID-19 infection; one died in the CP group from an ischemic stroke. CONCLUSIONS: No differences were observed in long-term antibody titers in unvaccinated patients that received CP or placebo after severe COVID-19 pneumonia.

ABO blood group does not influence the level of anti-SARS-CoV-2 antibodies in convalescent plasma donors.

BACKGROUND: The association of the ABO blood group with COVID-19 disease has been confirmed by several studies, with the blood group A patients being more susceptible and prone to a more severe clinical course of the disease. Additionally, several authors also addressed the association of ABO-types and the levels of anti-SARS-CoV-2 antibodies in convalescents, mostly supporting a theory that the non-O blood group convalescents present with higher levels of anti-SARS-CoV-2 antibodies. STUDY DESIGN AND METHODS: Since previous findings were based on small convalescent cohorts, we quantified the anti-SARS-CoV-2 antibody levels in a total of 3187 convalescent plasma donors with three commercial serological and one standard neutralizing antibody test. The majority of donors had undergone a mild form of the disease and the median time of sampling was 66 days after diagnosis. RESULTS: None of the antibody quantitation results showed any significant association with the ABO blood group types. The same result was evident in the subgroup of vaccinated individuals (n = 370) and the subgroups when stratified according to post-COVID-19 periods (0-60, 60-120, and 120-180 days). CONCLUSION: In conclusion, we found no evidence to confirm that the ABO blood group types influence the level of SARS-CoV-2 antibody response in COVID-19 convalescent plasma donors.

Sexual risk behavior questions: Understanding and mitigating donor discomfort.

BACKGROUND: Blood operators are working to improve donor screening and eligibility for gay, bisexual and other men who have sex with men (gbMSM), and trans and nonbinary donors. Many consider screening all donors for specific sexual risk behaviors to be a more equitable approach that maintains the safety of the blood supply. Feasibility considerations with this change include ensuring donor understanding of additional sexual behavior questions and minimizing donor loss due to discomfort. STUDY DESIGN AND METHODS: Qualitative one-on-one interviews were conducted with Canadian whole blood and plasma donors (N = 40). A thematic analysis was conducted to assess participants' understandings of the questions, examine their comfort/discomfort, and identify strategies to mitigate donor discomfort. RESULTS: All participants understood what the sexual behavior questions were asking and thought the questions were appropriate. Themes related to comfort/discomfort include: their expectations of donor screening, social norms that they bring to donation, whether their answer felt like personal disclosure, knowing the reasons for the question, trusting confidentiality, confidence in knowing their sexual partner's behavior, and potential for the question to be discriminatory. Strategies to mitigate discomfort include: providing an explanation for the questions, forewarning donors of these questions, reducing ambiguity, and using a self-administered questionnaire. CONCLUSION: While many blood operators and regulators view the move to sexual behavior-based screening for all donors as a significant paradigmatic shift, donors may not perceive additional sexual behavior questions as a significant change to their donation experience. Further research is needed to evaluate the effectiveness of strategies to mitigate donor discomfort.

Understanding the experiences of plasma donors in Canada's new source plasma collection centres during COVID-19: A qualitative study.

BACKGROUND AND OBJECTIVES: To address a national concern over the sufficiency of plasma, Canadian Blood Services (CBS) initiated a proof-of-concept programme with three new source plasma collection centres, aiming to demonstrate a cost-effective template for future source plasma collection and to alleviate the concerns and risks associated with the dependence on the United States. This study uses social capital as a framework to assess the success of the proof-of-concept collection centres. MATERIALS AND METHODS: One-hundred and one qualitative interviews with source plasma donors in three new source plasma centres in Canada were carried out. RESULTS: CBS played a critical role in motivating whole-blood donors to switch to plasma donation by building on their identity as a donor and facilitating access. Community was central to ensuring that donors returned. The importance of the social network was apparent through relationships participants developed with staff and through the relationships that staff had with each other. Donors wanted to understand more about the uses of plasma so that they could promote donation through their social networks outside the centre. CONCLUSION: Campaigns to convert existing blood donors to plasma donors should build on their identity as a donor and structure the centre as a safe and welcoming place. To retain donors, blood collection agencies should emphasize community by facilitating staff ability to work well together and connect with the donor. Blood operators have the potential to expand existing social networks and foster trust through the dissemination of knowledge about plasma more broadly in more diverse communities.

Hepatitis A Virus Incidence Rates and Biomarker Dynamics for Plasma Donors, United States.

The United States is currently affected by widespread hepatitis A virus (HAV) outbreaks. We investigated HAV incidence rates among source plasma donors in the United States since 2016. Serial donations from HAV-positive frequent donors were analyzed for common biologic markers to obtain a detailed picture of the course of infection. We found a considerable increase in incidence rates with shifting outbreak hotspots over time. Although individual biomarker profiles were highly variable, HAV RNA typically had a high peak and a biphasic decrease and often remained detectable for several months. One donor had a biomarker pattern indicative of previous exposure. Our findings show that current HAV outbreaks have been spilling over into the plasma donor population. The detailed results presented improve our comprehension of HAV infection and related public health aspects. In addition, the capture of full RNA curves enables estimation of HAV doubling time.

Donors for SARS-CoV-2 Convalescent Plasma for a Controlled Clinical Trial: Donor Characteristics, Content and Time Course of SARS-CoV-2 Neutralizing Antibodies.

BACKGROUND: Convalescent plasma is one of the treatment options for COVID-19 which is currently being investigated in many clinical trials. Understanding of donor and product characteristics is important for optimization of convalescent plasma. METHODS: Patients who had recovered from CO-VID-19 were recruited as donors for COVID-19 convalescent plasma (CCP) for a randomized clinical trial of CCP for treatment of severe COVID-19 (CAPSID Trial). Titers of neutralizing antibodies were measured by a plaque-reduction neutralization test (PRNT). Correlation of antibody titers with host factors and evolution of neutralizing antibody titers over time in repeat donors were analysed. RESULTS: A series of 144 donors (41% females, 59% males; median age 40 years) underwent 319 plasmapheresis procedures providing a median collection volume of 850 mL and a mean number of 2.7 therapeutic units per plasmapheresis. The majority of donors had a mild or moderate course of COVID-19. The titers of neutralizing antibodies varied greatly between CCP donors (from <1:20 to >1:640). Donor factors (gender, age, ABO type, body weight) did not correlate significantly with the titer of neutralizing antibodies. We observed a significant positive correlation of neutralization titers with the number of reported COVID-19 symptoms and with the time from SARS-CoV-2 diagnosis to plasmapheresis. Neutralizing antibody levels were stable or increased over time in 58% of repeat CCP donors. Mean titers of neutralizing antibodies of first donation and last donation of repeat CCP donors did not differ significantly (1:86 at first compared to 1:87 at the last donation). There was a significant correlation of neutralizing antibodies measured by PRNT and anti-SARS-CoV-2 IgG and IgA antibodies which were measured by ELISA. CCP donations with an anti-SARS-CoV-2 IgG antibody content above the 25th percentile were substantially enriched for CCP donations with higher neutralizing antibody levels. CONCLUSION: We demonstrate the feasibility of collection of a large number of CCP products under a harmonized protocol for a randomized clinical trial. Titers of neutralizing antibodies were stable or increased over time in a subgroup of repeat donors. A history of higher number of COVID-19 symptoms and higher levels of anti-SARS-CoV-2 IgG and IgA antibodies in immunoassays can preselect donations with higher neutralizing capacity.

Prediction of the anti-RhD donor population size for managerial decision-making.

BACKGROUND: Rhesus D (RhD)-negative women pregnant with a RhD-positive child receive prophylactic injections to prevent haemolytic disease of the newborn. Because of the success of the prophylaxis, the number of naturally immunized women has decreased, thereby also decreasing the number of potential donors who provide the plasma from which the prophylaxis is made. As the current donor pool is ageing, the availability of the prophylaxis is threatened. OBJECTIVES: Objectives are to investigate whether the anti-D population and the changes therein can be described by a relatively simple model, to determine the impact of ageing of the anti-D donors on the decline of the population and how many new donors should be recruited to meet future supply demand. METHODS: Data on Dutch anti-D donors in 1994-2013 were used to simulate the donor population size and age composition for various donor recruitment scenarios. RESULTS: With a continuous influx of 27 new donors per year and a donor stopping rate of 10% per year, the population size will stabilize at 195 donors, with 2·3% of donors stopping annually due to reaching the donor age limit. A formula is derived to estimate which donor recruitment and retention efforts are required to maintain a prespecified donor pool. CONCLUSION: A relatively simple model can already describe and predict the size of the anti-D donor population and the impact of ageing accurately.

The prevalence of hepatitis A virus and parvovirus B19 in source-plasma donors and whole blood donors in China.

AIMS: To compare the prevalence of hepatitis A virus (HAV) and human parvovirus B19 (B19V) between source-plasma (SP) donors and whole blood (WB) donors. BACKGROUND: In China, source plasma is in severe shortage while plasma recovered from WB is in surplus. Thus, the government is considering transferring the recovered plasma (RP) to produce plasma derivatives. HAV and B19V are two pathogens threatening the safety of plasma-based derivatives. However, there is no data about if transferring of the RP to produce plasma derivatives will increase the risk of HAV and B19V infection. Thus, we compared the prevalence of HAV and B19V between SP donors and WB donors in this study. METHODS: A total of 5030 samples from SP donors and 5040 samples from WB donors were collected. All the samples were tested for HAV RNA and B19V DNA and tested for HAV IgM by enzyme-linked immunosorbent assay (ELISA). RESULTS: The prevalence of B19V DNA was 0.06% (95% confidence interval (CI), 0-0.09%) in WB donors and 0.079% (95% CI, 0-0.12%) in SP donors, respectively. No significant difference was found in the prevalence of B19V DNA between SP donors and WB donors. The prevalence of anti-HAV IgM in SP donors was 0.079% whereas no WB donor sample was found anti-HAV IgM reactive. CONCLUSIONS: The transfer of RP to producing plasma derivatives will not increase the risk of transmission of HAV and B19 through plasma products.

Incidence of SARS-CoV-2 during the Omicron wave: Results of a longitudinal serosurvey in Québec, Canada.

OBJECTIVES: Conventional serological approaches lack sensitivity for the detection of recent SARS-CoV-2 infections in vaccinated individuals, as these individuals exhibit a blunted anti-nucleocapsid (N) response. This limitation was recently addressed by the development of a "ratio-based approach", which compares longitudinally collected specimens. Here, we used this approach to estimate the incidence of SARS-CoV-2 infection and reinfection in Québec (Canada) during the Omicron wave. METHODS: Consenting plasma donors were included if they donated plasma before December 15, 2021 and during six consecutive periods of ~ 3 months between December 15, 2021 and July 7, 2023 (study period). Anti-N levels were measured with an enzyme-linked immunosorbent assay, and seroconversion was characterized by a ratio of ≥ 1.5 between the optical density of two consecutive samples. RESULTS: Among the 254 donors, the adjusted proportion of donors (95% confidence interval [CI]) with a new infection ranged between 18.1% (13.2‒23.0) and 24.2% (18.8‒29.7) over Periods 1-5 and fell to 7.9% (4.9‒11.0) during Period 6. During the study period, the proportion of newly infected donors decreased among those aged < 60 (Period 1 = 31.6%, Period 5 = 4.4%), but increased among those aged ≥ 70 (Period 1 = 0.3%, Period 6 = 10.3%). Throughout the study period, 72 (28.3%) reinfections occurred, including two seroconversion events in a single donor. Overall, 87.4% (95% CI = 82.7‒91.2) were infected by SARS-CoV-2 at least once during the study period. CONCLUSION: The vast majority of the Québec population may have been infected during the Omicron wave. This longitudinal survey demonstrates the usefulness of the "ratio-based approach" for identifying both new infections and reinfections in a vaccinated population.

RéSUMé: OBJECTIFS: Les approches sérologiques classiques démontrent un manque de sensibilité pour la détection des infections récentes par le SRAS-CoV-2 chez les personnes vaccinées, car ces dernières présentent une réponse anti-nucléocapside (N) peu élevée. Cette limitation a été récemment surmontée suite au développement d'une « approche basée sur les ratios ¼, qui compare des échantillons collectés de manière longitudinale. Nous avons utilisé cette approche pour estimer l'incidence de l'infection et de la réinfection par le SRAS-CoV-2 au Québec (Canada) pendant la vague Omicron. MéTHODES: Les donneurs de plasma consentants étaient inclus dans l'étude s'ils avaient donné du plasma avant le 15 décembre 2021 et pendant six périodes consécutives de 2 à 3 mois entre le 15 décembre 2021 et le 7 juillet 2023 (période d'étude). Les taux d'anti-N ont été mesurés par ELISA et la séroconversion a été caractérisée par un rapport ≥ 1,5 entre la densité optique de deux échantillons consécutifs. RéSULTATS: Parmi les 254 donneurs, le risque ajusté (IC 95 %) d'infection a varié entre 18,1 % (13,2‒23,0) et 24,2 % (18,8‒29,7) au cours des périodes 1 à 5 et a chuté à 7,9 % (4,9‒11,0) au cours de la période 6. Au cours de la période d'étude, le risque d'infection a diminué chez les donneurs âgés de moins de 60 ans (période 1 = 31,6 %, période 5 = 4,4 %), mais a augmenté chez ceux âgés de ≥ 70 ans (période 1 = 0,3 %, période 6 = 10,3 %). Tout au long de la période d'étude, 72 (28,3 %) réinfections se sont produites (c'est-à-dire deux événements de séroconversion chez un même donneur). Dans l'ensemble, 87,4 % (IC 95 % = 82,7‒91,2) ont été infectés par le SRAS-CoV-2 au moins une fois au cours de la période d'étude. CONCLUSION: La grande majorité de la population québécoise pourrait avoir été infectée lors de la vague Omicron. Cette enquête longitudinale démontre l'utilité de l'approche basée sur les ratios pour identifier les nouvelles infections et les réinfections dans une population vaccinée.

Parvovirus B19 DNA and antibodies in Chinese plasma donors, plasma pools and plasma derivatives.

Background: Human parvovirus B19 (B19V) is a common contaminant found in plasma pools and plasma derivatives. Previous studies were mainly focused on limited aspects, further assessment of prevalence of B19V DNA and antibodies in plasma donors, the contamination of B19V in pooled plasma and plasma derivatives should be performed in China. Study Design and Methods: Individual plasma donors' samples from four provinces and pooled plasma from four Chinese blood product manufacturers were collected and screened using B19V DNA diagnostic kits between October 2018 and May 2020. The positive samples were investigated for the seroprevalence of B19V antibodies and subjected to sequence analysis and alignment for phylogenetic studies. Moreover, 11 plasma donors who were B19V DNA-positive at their first testing were also followed during the later donation period. Additionally, 400 plasma pools and 20 batches of plasma derivatives produced by pooled plasma with a viral load of B19V DNA exceeding 104IU/mL were also collected and tested for B19V DNA and antibodies. Objectives: To comprehensively and systematically determine the frequency and viral load of B19V DNA in plasma donors, pooled plasma, and plasma derivatives from four Chinese blood product manufacturers. Results: A total of 17,187 plasma donors were analyzed and 44 (0.26%) specimens were found positive for B19V DNA. The quantitative DNA levels ranged from 1.01 × 101 to 5.09 × 1012 IU/mL. Forty-four DNA-positive specimens were also investigated for the seroprevalence of B19V antibodies, 75.0% and 2.3% of which were seropositive for B19V IgG and IgM antibodies, respectively. The phylogenic analyses showed that the prevalent genotypes in the four provinces' plasma donors belonged to B19V Genotype 1. Eleven individual plasma donors who were B19V DNA-positive at the first donation were then followed for a period, and in general, the DNA levels of B19V gradually decreased. Moreover, 64.8% (259/400) of the pooled plasma was contaminated by B19V, with concentrations of 1.05 × 100-3.36 × 109IU/mL. Approximately 72.6% of the DNA-positive plasma pools were only moderately contaminated (<104 IU/mL), while 27.4% contained >104 IU/mL. Twenty batches of plasma derivatives produced by pooled plasma with a viral load of B19V DNA exceeding 104IU/mL were also tested. B19V was detected in 5/5 PCC samples and 5/5 factor VIII samples but was not found in the intravenous immune globulin and albumin samples. Conclusion: The contamination of B19V in pooled plasma and plasma-derived clotting factor concentrates is serious. Whether B19V nucleic acid testing (NAT) screening of plasma and plasma derivatives is launched in China, blood product manufacturers should spontaneously perform B19V NAT screening in plasma donors and mini-pool plasma. These measures can ensure that samples with high titer B19V DNA are discarded in order to prevent and control this transfusion transmitted virus.

Lessons learned: A look back at the performance of nine COVID-19 serologic assays and their proposed utility.

BACKGROUND: Serologic assays for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been proposed to assist with the acute diagnosis of infection, support epidemiological studies, identify convalescent plasma donors, and evaluate vaccine response. METHODS: We report an evaluation of nine serologic assays: Abbott (AB) and Epitope (EP) IgG and IgM, EUROIMMUN (EU) IgG and IgA, Roche anti-N (RN TOT) and anti-S (RS TOT) total antibody, and DiaSorin (DS) IgG. We evaluated 291 negative controls (NEG CTRL), 91 PCR positive (PCR POS) patients (179 samples), 126 convalescent plasma donors (CPD), 27 healthy vaccinated donors (VD), and 20 allogeneic hematopoietic stem cell transplant (HSCT) recipients (45 samples). RESULTS: We observed good agreement with the method performance claims for specificity (93-100%) in NEG CTRL but only 85% for EU IgA. The sensitivity claims in the first 2 weeks of symptom onset was lower (26-61%) than performance claims based on > 2 weeks since PCR positivity. We observed high sensitivities (94-100%) in CPD except for AB IgM (77%), EP IgM (0%). Significantly higher RS TOT was observed for Moderna vaccine recipients then Pfizer (p-values < 0.0001). A sustained RS TOT response was observed for the five months following vaccination. HSCT recipients demonstrated significantly lower RS TOT than healthy VD (p < 0.0001) at dose 2 and 4 weeks after. CONCLUSIONS: Our data suggests against the use of anti-SARS-CoV-2 assays to aid in acute diagnosis. RN TOT and RS TOT can readily identify past-resolved infection and vaccine response in the absence of native infection. We provide an estimate of expected antibody response in healthy VD over the time course of vaccination for which to compare antibody responses in immunosuppressed patients.

An Exploratory Study of the Differences in Attitudes and Motives Regarding COVID-19 Plasma Donation.

Background: Understanding the attitude and motives and differences between voluntary and replacement blood donation is the key to the sustainable availability of this precious resource. This study aimed to assess the attitude and motives for convalescent plasma (CP) donation in the recovered COVID-19 plasma donors and further understand the differences between voluntary and replacement donation. Materials and Methods: This prospective cross-sectional survey-based study was conducted among500 COVID-19 recovered blood donors who visited for CP donation at a tertiary care super-speciality centre in northern India. Data were collected using a structured questionnaire based on donor attitude, motives, and belief, which was validated by the experts of Psychiatry, Transfusion Medicine, and Epidemiology and was administered by the online medium. Results: The study's findings depicted that voluntary plasma donors were previously regular blood donors (36.8%) compared to replacement plasma donors (26.4%). Almost all voluntary donors (99.5%) showed altruistic reasons to donate plasma and expressed that donating plasma is a good way to save a life, and it was more than for replacement plasma donors (p=0.004). The motives of most voluntary plasma donors were to contribute to society, and they believed that donating plasma is a good way, while it was not the case for most replacement plasma donors (p=0.02). Voluntary donors were more eagerly willing to donate plasma to help COVID sufferers (40.9%) when compared to replacement donors (33.2%) (p=0.037). Conclusion: Most voluntary plasma donors were regular whole blood donors and were keen to contribute to society. Convalescent plasma donation during this time of grief and loss was considered a moral responsibility by voluntary donors. The impact of media was more highly perceived in voluntary plasma donors when compared to replacement donors.

Constraints and challenges in convalescent plasma collection amidst the Covid 19 pandemic- strategies and recommendations to overcome these.

BACKGROUND: COVID 19 is an acute respiratory disease caused by infection by the virus SARS-COV-2 and has been declared as a pandemic whose specific treatment is still not established. One of the options in the treatment is Convalescent plasma (CP) therapy when there is presence of required amount of neutralizing antibodies in the plasma of recovered COVID patients. Our objective was to analyze the challenges and the constraints encountered in motivation of COVID 19 recovered persons to come for the screening procedures and to convince the selected persons to come for Plasma donation voluntarily. MATERIAL & METHODS: The present retrospective observational study was conducted for a period of five and half months. Out of 1515 number of persons contacted telephonically for Plasma donation, 1291 persons came for screening of whom 1028 persons were eligible for donation, 263 cases were deferred and 966 persons finally donated. RESULTS: Maximum number of acceptance cases were from males-(98.7%). Of the accepted cases, (41.73%) were from the 18-30 years' age group. 33.94% were from blood group 'O' Rh D positive giving maximum contribution from any blood group. 38.3% of the accepted cases had resolution of all COVID symptoms within time period of 28-40 days. Maximum number of accepted individuals (39.75%) had suffered from multiple symptoms followed by 39.02% of asymptomatic persons. Highest number of Plasma donation was contributed by Odisha Government Police personnel (51.56%). DISCUSSION: In this global ongoing pandemic, the "Fear Factor of contracting the disease" has acted as a major challenge in motivating and convincing a COVID recovered patient for plasma donation. The challenge before the medical professionals was to motivate, educate and convince the potential donors and the society about the likely benefits of convalescent plasma. This could be finally overcome with the help of positive orientation through social and conventional media as well as mass appeal from government side on the benefits of plasma therapy in saving lives in the present pandemic.